Cooling device for a current converter module

1. A cooling device for an electrical power component, comprising: a cooling circuit operated with a liquid coolant in a flow direction; a heat exchanger connected in the cooling circuit, the heat exchanger is coupled to the power component in a thermally conductive manner; a cooler for cooling the coolant, which cooler, viewed in the flow direction of the coolant, is connected behind the heat exchanger in the cooling circuit; an elongated distributor pipe, which, viewed in the flow direction of the liquid coolant, is connected behind the cooler and in front of the heat exchanger by means of respective cooling liquid channels in the cooling circuit, the cross-section of the distributor pipe is greater than the flow cross-section of the respective cooling liquid channels and the distributor pipe is mounted parallel to a gravity vector; a pump connected in the cooling circuit for maintaining circulation of the coolant; temperature sensors for detecting temperature of the heat exchanger and for detecting temperature of ambient air; a heater for heating the coolant, the heater is located in the distributor pipe; and a control unit to analyze signals from the temperature sensors and to switch the heater on when the power component is not in operation and the heat exchanger assumes a lower temperature than the ambient air, so that without using the pump the heated coolant is circulated by natural convection in the cooling circuit and heats the heat exchanger.

2. The cooling device according to claim 1 , wherein the power component is a bipolar transistor with an insulated-gate bipolar transistor.

3. The cooling device according to claim 1 , wherein the coolant is a water/ethanol mixture.

4. The cooling device according to claim 1 , wherein the heater consists of a heating coil, which is disposed beneath the distributor pipe.

5. A current converter module for connection to a wind power system or solar power system for network supply, the current converter module including and has a plurality of power components coupled to respective heat exchangers of a cooling device, the cooling device comprising: a cooling circuit operated with a liquid coolant in a flow direction; the heat exchangers are connected in the cooling circuit and coupled to the respective power components in a thermally conductive manner; a cooler for cooling the coolant, which cooler, viewed in the flow direction of the coolant, is connected behind the heat exchangers in the cooling circuit; an elongated distributor pipe, which, viewed in the flow direction of the liquid coolant, is connected behind the cooler and in front of the heat exchangers by means of respective cooling liquid channels in the cooling circuit, the cross-section of the distributor pipe is greater than the flow cross-section of the respective cooling liquid channels and the distributor pipe is mounted parallel to a gravity vector; a pump connected in the cooling circuit for maintaining circulation of the coolant; temperature sensors for detecting temperature of the heat exchanger and for detecting temperature of the ambient air; a heater for heating the coolant, the heater is located in the distributor pipe; and a control unit to analyze signals from the temperature sensors and to switch the heater on when the power component is not in operation and the heat exchanger assumes a lower temperature than the ambient air, so that without using the pump the heated coolant is circulated by natural convection in the cooling circuit and heats the heat exchanger.

6. The cooling device according to claim 1 , and further comprising a ventilation valve disposed above the distributor pipe.